The invention relates generally to storm water drains or catch basins, and more particularly relates to valves or other shut-off mechanisms to preclude passage of storm water run-off through the catch basin. Even more particularly, the invention relates to such valves or other shut-off mechanisms that are automatically responsive to the presence of hazardous liquids, such as oil, chemicals or the like, in the storm water run-off.
Storm water catch basins are typically concrete structures buried below grade in paved areas, such as alongside streets or in parking lots, the catch basins being covered by heavy removable grates. The catch basins communicate with a storm water conduit system such that storm water run-off passes through the catch basins and then into the conduit system to be delivered to a remote location. It is known to provide filtering devices in the catch basins to filter out and retain trash, debris, particulate matter or the like from the storm water run-off for later disposal, such as shown for example in U.S. Pat. No. 5,575,925 to Logue, Jr. In addition to solid matter, however, hazardous liquids such as oil, gasoline, chemicals or the like may enter the catch basins due to accidental leaks or improper discharge of hazardous liquid containers, and these hazardous liquids will pass through these basic filters into the disposal system.
It is an object of this invention to provide an automatic liquid valve adapted for use within a catch basin, whereby such valve remains open in the passive state but closes to seal off the catch basin in the event hazardous liquids are encountered in the storm water run-off.